Buggy code:
public static final String SERVER_NAME = "server" ; ServerService ( final Bootstrap . Configuration configuration , final ControlledProcessState processState , final OperationStepHandler prepareStep , final BootstrapListener bootstrapListener , final RunningModeControl runningModeControl , final AbstractVaultReader vaultReader , final RemoteFileRepository remoteFileRepository ) { } static ProcessType getProcessType ( ServerEnvironment serverEnvironment ) { } public static void addService ( final ServiceTarget serviceTarget , final Bootstrap . Configuration configuration , final ControlledProcessState processState , final BootstrapListener bootstrapListener , final RunningModeControl runningModeControl , final AbstractVaultReader vaultReader , final RemoteFileRepository remoteFileRepository ) { } public synchronized void start ( final StartContext context ) throws StartException { } protected void boot ( final BootContext context ) throws ConfigurationPersistenceException { boolean ok ; try { final ServerEnvironment serverEnvironment = configuration . getServerEnvironment ( ) ; final ServiceTarget serviceTarget = context . getServiceTarget ( ) ; serviceTarget . addListener ( ALL , bootstrapListener ) ; final File [ ] extDirs = serverEnvironment . getJavaExtDirs ( ) ; final File [ ] newExtDirs = Arrays . copyOf ( extDirs , ( ( extDirs . length ) + 1 ) ) ; newExtDirs [ extDirs . length ] = new File ( serverEnvironment . getServerBaseDir ( ) , "lib//ext" ) ; serviceTarget . addService ( JBOSS_DEPLOYMENT_EXTENSION_INDEX , new ExtensionIndexService ( newExtDirs ) ) . setInitialMode ( ON_DEMAND ) . install ( ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_SERVICE_MODULE_LOADER , new DeploymentUnitProcessor ( ) { @ Override public void deploy ( DeploymentPhaseContext phaseContext ) throws DeploymentUnitProcessingException { phaseContext . getDeploymentUnit ( ) . putAttachment ( SERVICE_MODULE_LOADER , injectedModuleLoader . getValue ( ) ) ; phaseContext . getDeploymentUnit ( ) . putAttachment ( EXTERNAL_MODULE_SERVICE , injectedExternalModuleService . getValue ( ) ) ; } @ Override public void undeploy ( DeploymentUnit context ) { context . removeAttachment ( SERVICE_MODULE_LOADER ) ; } } ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_EXPLODED_MOUNT , new DeploymentRootExplodedMountProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_MOUNT , new DeploymentRootMountProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_MANIFEST , new ManifestAttachmentProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_ADDITIONAL_MANIFEST , new ManifestAttachmentProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_SUB_DEPLOYMENT , new SubDeploymentProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_MODULE_IDENTIFIERS , new ModuleIdentifierProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_ANNOTATION_INDEX , new AnnotationIndexProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_PARSE_JBOSS_ALL_XML , new JBossAllXMLParsingProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_JBOSS_DEPLOYMENT_STRUCTURE , new DeploymentStructureDescriptorParser ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , STRUCTURE , STRUCTURE_CLASS_PATH , new ManifestClassPathProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , PARSE , PARSE_DEPENDENCIES_MANIFEST , new ManifestDependencyProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , PARSE , PARSE_COMPOSITE_ANNOTATION_INDEX , new CompositeIndexProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , PARSE , PARSE_EXTENSION_LIST , new ManifestExtensionListProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , PARSE , PARSE_EXTENSION_NAME , new ManifestExtensionNameProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , PARSE , PARSE_SERVICE_LOADER_DEPLOYMENT , new ServiceLoaderProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_MODULE , new ModuleDependencyProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_SAR_MODULE , new ServiceActivatorDependencyProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_CLASS_PATH , new ModuleClassPathProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_EXTENSION_LIST , new ModuleExtensionListProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_SUB_DEPLOYMENTS , new SubDeploymentDependencyProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_JDK , new ServerDependenciesProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_VISIBLE_MODULES , new DeploymentVisibilityProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_DRIVERS , new DriverDependenciesProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , CONFIGURE_MODULE , CONFIGURE_MODULE_SPEC , new ModuleSpecProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , POST_MODULE , POST_MODULE_INSTALL_EXTENSION , new ModuleExtensionNameProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , POST_MODULE , POST_MODULE_REFLECTION_INDEX , new InstallReflectionIndexProcessor ( ) ) ; <START_BUG> DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , POST_MODULE , POST_MODULE_TRANSFORMER , new ClassFileTransformerProcessor ( ) ) ; <END_BUG> DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , INSTALL , INSTALL_SERVICE_ACTIVATOR , new ServiceActivatorProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , CLEANUP , CLEANUP_REFLECTION_INDEX , new CleanupReflectionIndexProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , CLEANUP , CLEANUP_ANNOTATION_INDEX , new CleanupAnnotationIndexProcessor ( ) ) ; DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , DEPENDENCIES , DEPENDENCIES_SEAM , new org . jboss . as . server . deployment . integration . Seam2Processor ( serviceTarget ) ) ; DeploymentStructureDescriptorParser . registerJBossXMLParsers ( ) ; try { ok = boot ( extensibleConfigurationPersister . load ( ) , false ) ; if ( ok ) { finishBoot ( ) ; } } finally { INSTANCE . clearDeployerMap ( ) ; } } catch ( Exception e ) { ROOT_LOGGER . caughtExceptionDuringBoot ( e ) ; ok = false ; } if ( ok ) { bootstrapListener . tick ( ) ; } else { ROOT_LOGGER . unsuccessfulBoot ( ) ; System . exit ( 1 ) ; } } protected boolean boot ( List < ModelNode > bootOperations , boolean rollbackOnRuntimeFailure ) throws ConfigurationPersistenceException { } public void stop ( final StopContext context ) { }

Fix:
DeployerChainAddHandler . addDeploymentProcessor ( ServerService . SERVER_NAME , FIRST_MODULE_USE , FIRST_MODULE_USE_TRANSFORMER , new ClassFileTransformerProcessor ( ) ) ;